3. If the ratio of A to B is 3 : 2 and the ratio of B to C is 3:2, find
the ratio A:B: C. Are A, B, C are in continued proportion?
Answers
Answer:
9:6:4 this is the correct answer
Answer:
How to Solve Proportions?
- It is easy to calculate if ratios are proportional. To check if the ratio a: b and c: d is proportional.
- Multiply the first term with the last term: a x d
- Multiply the second term with the third term: b x c
- If the product of extreme terms is equal to the product of mean terms, then the ratios are proportional: a x d = b x c
Continued proportion
- Two ratios a: b and b: c is said to be in continued proportion if a: b = b: c. In this case, the term c is called the third proportion of a and b whereas b is called the mean proportion of between the terms a and c.
- When the terms a, b and c are in continued proportion, the following formula is derived:
- a/b = b/c
- Cross multiplying the terms gives; a x c =b x b, Therefore,
b² = ac
Step-by-step explanation:
Example 1
Find out if the following ratios are in proportion: 8:10 and 12:15.
Explanation
Multiply the first and fourth terms of the ratios.
8 × 15 = 120
Now multiply the second and third term.
10 × 12 = 120
Since the product of the extremes is equal to the product of the means,
Since, the product of means (120) = product of extremes (120),
Therefore, 8: 10 and 12:15 are proportional.
Example 2
Verify if the ratio 6:12::12:24 is proportion.
Explanation
This is a case of continued proportion, therefore apply the formula a x c =b x b,
In this case, a: b:c =6:12:24, therefore a=6, b=12 and c=24
Multiply the first and third terms:
6 × 24 = 144
Square of the middle terms:
(12) ² = 12 × 12 = 144
Therefore, the ratio 6:12:24 is in proportion.
Example 3
If 12:18::20: p. Find the value of x to make the ratios proportional?
Explanation
Given: 12: 18::20: p
Equate the product of extremes to the product of means;
⇒ 12 × p = 20 × 18
⇒ p = (20 × 18)/12
Solve for p;
⇒ p = 30
Hence, the value of p= 30
Example 4
Find the third proportional to 3 and 6.
Explanation
Let the third proportional be c.
Then, b² = ac
6 x 6 = 3 x c
C= 36/3
= 12
Thus, the third proportional to 3 and 6 is 12